§02e Jupiter — AIGP & Pre-Invocation — Absence postures and the signal-absent battery state
Mars® Spec › §02e Jupiter — AIGP & Pre-Invocation › Absence postures and the signal-absent battery state
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7. Absence postures and the signal-absent battery state
The declared absence posture of each registered source governs how the battery handles the case where a source produces no signal for a given invocation.
Signal-required absence. Where a source’s absence posture is signal-required and no signal is received, the battery records a typed gap referral at the pre-invocation signal locus. The gap referral identifies the source, the invocation, and the signal class expected. The battery may not proceed to a conforming verdict while a signal-required gap referral is open; no verdict is issued and a gap referral is emitted in its place pending signal resolution or explicit gap declaration.
Signal-optional absence. Where a source’s absence posture is signal-optional, absence is a valid declared state. The battery records a signal-absent entry for that source and proceeds. The declared-scope invariant (Field 5) reflects that the absent source’s evaluation is not included in the certified scope.
Signal-suppressed absence. Where the source was configured not to run, the battery records a suppression entry identifying the source, the suppression authority (the deployment configuration that suppressed it), and the governing-specification version under which suppression was declared. Suppression is not a conformance defect; it is a declared scope reduction that must appear in Field 5.
Global signal-absent posture. Where no pre-invocation signal sources are registered, the battery operates in the signal-absent posture: no pre-invocation links appear in the witness chain, cross-phase corroboration is not computed, and Field 5 declares that pre-invocation evaluation is outside the certified scope. This is a complete, valid battery posture. The certificate issued is sound for the post-invocation analysis it covers; it does not attest to pre-invocation governance.
Fail-closed base case. When no sound admissibility verdict arrives from a registered admissibility-gate source — because the source produced no signal, produced an indeterminate signal, or produced a signal that the battery cannot verify as having been soundly determined — the battery’s base-case disposition is REFUSE or REFER, never silent ADMIT. The battery does not forward the invocation on the basis of an absent or unverifiable verdict. A falsifier received from any registered source under any operating state forces REFUSE with no down-rating; a REFUSE finding received from a source may not be treated by the battery as REFER or ADMIT. A source registration record that declares a fallback output of ADMIT on absence or degradation is incompatible with the admissibility-gate source class; the battery treats such a signal as a W2 attestation only.
Spec-version drift detection. Every admissibility verdict produced by a W1 source is stamped with the governing-specification version under which it was rendered. Drift detection operates in two modes, both grounded in this version stamp: (a) input/population drift — comparison of the inbound prompt distribution against a recorded baseline, detecting shifts in what prompts are being submitted regardless of spec version; and (b) spec drift — re-binding a prior verdict’s recomputation witness to the current governing-specification version, detecting that the spec itself has changed such that a prompt previously admitted would now be refused, or vice versa. Spec drift re-binding is performed by applying the W1 witness’s derivation trace to the current spec version and comparing the resulting verdict to the recorded verdict; a change in verdict under the current spec version is a spec-drift event. Spec drift is a consequence of the delta-attestation lifecycle (§02b §5): a scope-restricting or scope-breaking amendment to the governing specification may change the admissibility verdict for prompts evaluated under the prior version. When a spec-drift event is detected, the prior verdict is flagged as stale and re-evaluation under the current spec version is triggered, or the fail-closed base case applies if re-evaluation cannot be performed. The two drift modes are jointly necessary for a complete drift-detection posture: input drift without spec drift detects distribution shift but misses spec changes; spec drift without input drift detects spec changes but misses the population-level effect. A source that implements only one mode declares this in its registration record.
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